Alleviating high PAPR and noise issues for optimized performance in ACO-OFDM-Based VLC systems

Visible Light Communication (VLC) is an emerging technology poised to complement radio frequency (RF) communication systems in various high-demand applications. By employing optical orthogonal frequency division multiplexing (O-OFDM) techniques, VLC enhances data transmission rates and minimizes intersymbol interference. Among these techniques, asymmetrically clipped O-OFDM (ACO-OFDM) is notable for its high power efficiency and superior performance. However, a significant challenge in ACO-OFDM-based VLC systems is the high peak-to-average power ratio (PAPR), which forces light-emitting diodes (LEDs) to operate beyond their linear range, leading to signal distortion, power inefficiency, thermal stress, and reduced LED lifespan. Additionally, high PAPR increases receiver complexity and limits system scalability, necessitating effective mitigation strategies for reliable VLC deployment. This study addresses the PAPR challenge by introducing a hybrid reduction strategy that combines precoding with nonlinear companding techniques. The proposed approach attains a PAPR reduction of 6.1855 dB compared to basic ACO-OFDM without degrading bit error rate (BER) performance. Additionally, the study enhances BER performance by integrating two noise mitigation models at the receiver. These models improve system performance by 2.275 dB relative to standard ACO-OFDM while maintaining the same BER level. When applied together, the PAPR reduction strategy and noise mitigation models yield a total PAPR diminution of 6.2611 dB and an enhancement in BER performance of 0.76 dB. A detailed comparative analysis with established methods from the literature confirms the efficiency and robustness of the proposed approach. This systematic evaluation underscores its potential to address key limitations of traditional ACO-OFDM, positioning it as a viable solution for next-generation VLC systems.